The present invention relates to the enchanced solubility of halogenated hydantoins in aqueous solutions by the addition thereto of a solubility agent selected from the group consisting of magnesium oxide, barium hydroxide, sodium bicarbonate, sodium carbonate, 5,5-dialkyl substituted hydantoins and mixtures thereof which agent increases the level of both free and total halogen in solution. The enchanced solubility of such materials renders them particularly suitable for use in toilet bowl applications.
The halogenation of hydantoins results in substitution at the N.sub.1 and N.sub.3 positions as shown in the following equation: ##STR1## X=Chlorine or bromine; R.sub.1, R.sub.2 =CH.sub.3 --and/or CH.sub.3 CH.sub.2 --.
Typical "hydantoins" are, for example, 5,5-dimethylhydantoin, 5-ethyl-5-methyl-hydantoin, 5,5-diethylhydantoin whose substitution in the 5-position is a function of the ketone used in synthesizing the "hydantoin" by the classical Bucherer-Bergs reaction.
A number of halogenated hydantoins are well-known for their bleaching and disinfecting properties. Their effectiveness in these applications is due to their ability to generate (release) positive halogen in aqueous solution.
In many applications, it is desirable to formulate the halogenated hydantoin in a shape retentive form, i.e., as a granule, tablet or briquette due to the inherently irritating and dusty nature of the compounds.
Halogenated derivatives of dimethylhydantoin (e.g. 1,3-dibromo-5,5-dimethylhydantoin; 1-bromo-3-chloro-5,5-dimethylhydantoin and 1,3-dichloro-5,5-dimethylhydantoin) are halogen donors typically utilized for various purposes. Thus, 1-bromo-3-chloro-5,5-dimethylhydantoin is used for swimming pool sanitizers, while 1,3-dichloro-5,5-dimethylhydantoin has been used successfully for bleaching (see, Kirk-Othmer, Encyclopedia of Chemical Technology, Volume 12, pp. 704-705, Wiley Interscience, 1980; and U.S. Pat. No. 2,779,764 to Patterson).
Halogenated derivatives of dimethylhydantoin are fine, dusty powders which are difficult to compact into solid forms of high integrity or to granulate. Compaction of 1,3-dichloro-5,5-dimethylhydantoin has been proposed in U.S. Pat. No. 4,242,216 to Daugherty et al. Recently, in my co-pending application Ser. No. 465,175 filed Feb. 9, 1983, titled "Halogenated Hydantoins" substantially dust-free, free flowing and compactible halogenated methylethyl hydantoins are described.
Halogenated hydantoins are potentially useful in a wide variety of applications which heretofore have been primarily serviced through the use of hypohalite bleaches such as sodium hypochlorite and the like. Such applications include:
fabric bleaching; PA1 swimming pool disinfection; PA1 spa or hot tub disinfection; PA1 water cooling tower disinfection; PA1 automatic dishwasher-bleaching; and PA1 toilet bowl cleaners.
These applications, however, require the generation of controlled concentrations of "free" halogen. Commercially used halohydantoins generally are in the form of hard compressed tablets and briquettes having a relatively low surface area. Such solid halohydantoins do not dissolve as rapidly as the powder or granules, and in many applications it is desirable to achieve enhanced solubility of the halohydantoins.
Accordingly, it is a primary object of the present invention to provide a means for controlling the concentration of free halogen in aqueous solutions of halohydantoins.
It is a further object of the present invention to provide method for increasing the rate of dissolution of halogenated hydantoins.
A still further object of the present invention is to provide an enhanced method and composition for the cleaning and disinfection of toilet bowls.
These and other objects will be more apparent from the following discussion.